Abstract and Applied Analysis
Volume 2011 (2011), Article ID 534120, 15 pages
http://dx.doi.org/10.1155/2011/534120
Research Article

Fuzzy Stability of a Functional Equation Deriving from Quadratic and Additive Mappings

Sun Sook Jin and Yang-Hi Lee

Department of Mathematics Education, Gongju National University of Education, Gongju 314-711, Republic of Korea

Received 14 March 2011; Accepted 22 June 2011

Academic Editor: Yoshikazu Giga

Copyright © 2011 Sun Sook Jin and Yang-Hi Lee. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We investigate a fuzzy version of stability for the functional equation 𝑓 ( 2 𝑥 + 𝑦 ) + 𝑓 ( 2 𝑥 − 𝑦 ) + 2 𝑓 ( 𝑥 ) − 𝑓 ( 𝑥 + 𝑦 ) − 𝑓 ( 𝑥 − 𝑦 ) − 2 𝑓 ( 2 𝑥 ) = 0 in the sense of Mirmostafaee and Moslehian.